Means for regulating the output of pumps operated by the engines of automobiles or the like



Nov. 27, 1923 '1,475,508

R. ESNAULT-PELTERIE MEANS FOR REGULATTNG THE OUTPUT OF PUMPS OPERATED- BY THE ENGINES OF AUTOMOBILES OR THE LIKE Filed Aug. 16'. 1921 .0 v l 42 l [N1/fawn@ 2 4# f By Arron/Jars Patented Nov. 27, i923.

tlallplll STATS u'r aries- ROBERT EsNAULT-rnnrnmn, or raars, FRANCE.

MEANS FOR R-EGUIiAILlTCrv THE OUTPUT OF PUMPS OPERATED BYVTHE ENGINES OF Y AUTOIVIOBLES THE LIKE.

Application :filed August 16, 1921. VSerial No. 492,855.

To whom t may concern.'

Be it known that l, ROBERT EsNAUL'r- PnL'rERrE, a citizen of the RepublicA of France, residing'in Paris, France, have invented new and 'useful lmprovements in Means for Regulating the Output of Pumps Operated by the Engines of Automobiles or the like, which is fully set forth 'in the following specification.

vThis invention consists in an improved method and means for controlling the liquid Output of a pump, a method of control by which the output can be varied both automatically and at will, as will be explained later, and this by simple mechanical means which provide for a progressive and automatic change of speed of automobiles.

According to the present invention, the variation of the output ot a pump is obtained by the employment Vof an auxiliary piston having a variable stroke, the output of which reduces that ofthe pump working piston. When the two outputs are equal, the total output will be nothing and, on the contrary, when that of the'auxiliary piston is nothing the total output would be equal to that of the Working piston.

The principal feature of the present invention consists in the simplicityy of the means for accomplishing this result, the auxiliary piston being driven without the. aid of any mechanical member and simply by, means of the pressure developed in the body of the pump.

This auxiliary piston should have a large surface and a small stroke, so that only a small inertia is developed by its movement even when the latter is rapid. This allows its stroks to be controlled by an adjustable abutment, for example a screw, without the shock at the and of the stroke giving rise to any considerable absorption of energy.

If it becomes necessary to further diminish this small loss of work, it would be easy to arrange the abutment as an elastic mein ber (on account of the short stroke and the correspondingly small momentum,l a small` elasticity will be sufficient).

The screw ofthe abutment can be controlled directly by hand orby the intervention. of a yservo-motor. The description which-follows with respect to the kaccompanying drawing, given by way ofexample, willexplain .the manner inL which the in` -vention is carried out.

of a box or casing l separat-ed by a partie Y tion 2 into two parts provided respectively with an outlet 3 and an inlet t. l Y

The flaps or valves of delivery 5 and of suction 6 of each pump body are annular and formed by sheets of steel of small thickness (or example, O m/m 2 each) secured between two pieces 7 and 8, threaded one on the other and forming the seat of the valve, the circular pieces 8 being provided with arms, not shown in the drawing, which attach them to the pieces 7. As shown in Fig. 3 the valves 5 which are annular, carry openings 9 disposed cireularly in such a manner that the annular partinterior to these openings is held between pieces 7 and 8 and the exterior annular part formsthe valve at the edges of the pieces 7 and 8.

The two dotted circles of Fig. 3repre' sent the edges of the annular hole for the oil. The suction valves 6 are mounted in a similar manner between pieces 7 and v8, but it is the exterior annular part-which is held between these pieces, theopenings't) being disposed. towards the periphery, while the suction of the oil takes place through an annular surface nearerthe'centre.l

The end of the cylinderrof thepump lis formed by a movable piston 10, provided with piston rings and sliding in a cylindricalcompartment 11. The stroke of-this cylinder is limited in the following manner:-

lts upper end carries a flange 12 which in the lowest positionrests on a shoulder 13 carried by the cylindrical compartment 11; the spring 14 vconstantly urges the pistonv towards the base, and maintains lit thus in the lowest position as long as there is no pressure in the cavity 15 of the pump. When the pressure developed inthe body of the pumpcauses the piston 10 to rise, it abuts against thepiece 16, Belleville springs 17 being interposed, or anyv other slightly v elastic arrangement. V.The piece 16 itself traverses the pressed leather members'lt, which can, however,.be replacedby any other means for preventing leakage. (stuffing boxes or the like) and is continued at its upper part by the screw 19 which is'integral with the lever arm 20. lt is this piece 16 which constitutes the adjustable abutment for the piston.

The cavity 21 communicates by the pipe 22 with the suction chamber 23 of the pump. Preferably at this pipe and near the chamber 23Yan air chamber, not shown, should be arranged.

lt should be remarked that the end of the plunger piston 24 of the oil pump is in. the form of a very prolonged cone. rlhis is of great importance in order to avoid shocks and to allowthe action to take place at very high speeds. v Y

Obviously, the plunger piston should be guided in a perfect manner and for this reason it can be terminated in a crosshead 25 sliding in guides 26, which 'can be placed on the fixed base of the body of the suction pump 0r canbe cast with it. The crosshead of the piston can then be connected by a connecting rod 27 and acrank to the shaft of any motor. It will be understood that it may in certain cases be advantageous, notably for effecting the change of speeds of automobiles, to group in ya single block a motor with four Vcylinders and two pumps, so that the design is similar to the general arrangement of a motor with six cylinders.

There is also an advantage which is easily understood, in making` such pumps work in groups of two 180O apart, in order that the successive work of delivery and suction in each ofthem shall beintercalated respectively; in this way the variation of thetotal output is very much reduced. By means of groups of three at angles of 120 the output would be still more'regular (and in the same way in proportion asthe number of pumps working together is increased).

As always, if the number of the pumps is restricted, the output will undergo sensible variations, it is advisable to arrange on the deliverypipe 3 and on the Vsuction pipe 4 and in the neighbourhood of the pump, air chambers or preferably pistons resting on suitable springs which permit them .to circulate a volume aty least equal to half the cylinder of the plunger piston 24, in the case of a single pump, or a suiiicient fraction of this cylinder in the case of several pumps working together. ln order to control the lever 20, which is' integral with the screw 19 which controls the stroke of the compensating piston 10, any mode of regulation can be used. It is suiiicient to work this lever by any means suitable for turning the screw 19 and to lower it more or less. The regulation of this .lever may be effected. by a servo-motor such as represented in Fig. 2. By this means, the distribution valve 32 of the servo-motor is exposed on its face 33 to the pressure of a tachymetrical centrifugal pump keyed on the shaft of the motor and on its other face 34 to the pressure of a spring, of which the tension is regulated by the displacement of the'piece 35 by means of the hand lever 29. The space comprised between the piston 35 and the valve 32 is in communication by a pipe 36 with the suction of the tachymetrical centrifugal pump. This valve 32 is provided with two bent passages 37, 38 which, during the displacement of the said valve, register with eXtensions of the pipes 39, 40 and 41, the two first 39, 40 leading to the front end of a cylinder 42, and the third 41 to the rear end of the said cylinder 42. ln the cylinder, a movable piston 44 has its piston rod 43 connected to the arm 2O and consequently determines the angular movement of the screw 19.

ce y

It will be seen that vwhen the tension of Y the spring has been regulated by displacing the piston 36 by the aid of the handlever 29, the arrangement of this servo-motor con'-` stitutes a speed regulator affecting the power absorbed by the pump by the control of the output of oil. Y When, in fact, the speed of the motor increases, the pressure of the oil acting on the face 33 of the valve l32 increases since the centrifugal pump turns more quickly. rl`he slide lvalve 32 is then displaced towards the left, compressing the spring, and the oil passing through the passages 38 and 41 drives the piston 44 towards the left, which turns the screw 19.

Obviously, the connections will be so arranged that when the speed'of the motor increases and consequently the pressure rises in the tachymetrical pump, the screw Ydiminishing the stroke of the latter and augmenting relatively the outputy of the pump, while increasing the power absorbed.

By moving the hand lever 29, the tension of the spring can be varied, which causes y the small movable piston to take up differ'A ent positions of equilibrium corresponding td different speeds of the motor.

lt is evident that the present invention is not limited to the arrangement shown, but

that it can be applied to any type of pump.

wherein an end or movable part has aV small and variable stroke, so that the output of the said pump may be varied automatically or at will.

rl'his automatic variation of the output permits, as has been said,of a progressive and automatic change of speed ofautomobiles. Y hydraulic motor which drives the wheels is restricted so .as to have an invariable output, when the vehicle approaches an incline. the following phenomena will occur.

As the resisting torque of the wheels increases, the pressure at the admission of the motor pumps increases A proportionately; that is to say, at the delivery of the generln fact, if the respective pump or l iso? ator pumps which are the object of the present invention. The resisting torque opposed to the motor by the generator pump then increases equally and the said motor has a tendency to slow down. As soon as it slows down, the control of the movable abutment acts, as has been explained, in lessening the active surface of the cylinder of the generator pump, until the motor has taken up the speed which-the position of the hand lever 29 of Fig. 2 assigns to it. The output being thus lessened, the speed of the vehicle diminishes in the same proportion; the speed of the motor thus remaining constant.

It is seen that in this way the hand lever 29 of Fig. 2 determines at will the speed system of the motor depending on the position occupied by the said hand lever, the speed being constant for each position. It will thus he perceived that the variations of speed of the vehicle are obtained by the variations of admission to the motor, while the speed of rotation in the said motor remains constant during these changes of speed of the vehicle.

It is evident that itV would be possible to give the motor a single speed and not several speeds.

In this case hand lever 29 could be eliminated and the end 35 of the cylinder made immovable1 the spring which balances the pressure of the tachymetrical pump having a tension suitably adjusted beforehand, in order that the motor should turn at the desired speed.-

The control system in question presents the great advantage in its application to driving the screws of aeroplanes that the hand lever 29 of Fig. 2 can be placed in the position which determines the speed of rotation of the motor which is most favourable and that then the screw automatically takes the speed for which it absorbs the corresponding power.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is l. In a pump provided. with a piston and actuated by a. motor, a second piston and automatic means controlled by the motor for limiting the stroke of the second piston and for varying the output of the pump.

2. In a pump provided with a piston and actuated by a motor, a second piston having a large surface compared with that of the first piston and movable over a short length compared with the stroke of the first piston, by the direct action of the pressure of the liquid in the pump body, whereby the second piston will absorb but a small amount of visviva as compared with the energy transrnited by the pump, whose output isy modi- 3. In a pump provided with a piston and actuated by a motor, a second piston having a large surface compared with that of the first piston and movable, over a short length compared with the stroke of the first piston, by the direct action of the pressure of the liquid in the pump body, resilient means for limiting the stroke of the second piston in order that the movement of the piston and the shocks at the end of the stroke shall absorb but a-small part of the energy trans- Eiited by the pump, whose output is modi- 4. A pump comprising a cylinder filled with liquid, a piston movable in said cylinder, la conical end formed on said piston whereby eddies in the liquid are prevented during high speed mot-ion, suction and delivery Hap valves, a second piston having a large surface compared with that of the rst piston and movable, over a short length compared with the stroke of the first piston, by the direct laction of the pressure of the liquid in the pump body, resilient means for limiting the stroke of the second piston in order that the movement of the piston and the shocks at the end of the stroke shall absorb but a small part of the energy transmitted by the pump whose output is modied according to the action of the means limiting the stroke of the second piston.

5. A pump comprising a cylinder filled with liquid, a piston movable in said cylinder, a conical end formed on said piston, whereby eddies in the liquid are prevented during high speed motion, suction and delivery tlap valves, a second piston having a large surface compared with that of the first piston and movable over a short length compared with the stroke of the rst piston, a screw-threaded rod screwed into the bottom of the cylinder for the purpose of limiting the stroke of the latter, and means 'or'automatic `rotation of the screw-threaded rod and for thereby varying the output ofthe pump.

6. System of transmission of' a driving eil'ort, comprising in combination a motor, a generating pump adapted to be driven by said motor, a piston movable in the pump cylinder, a liquid filling the cylinder, a second piston disposed in the second cylinder and movable bythe pressure of the liquid, suction and delivery flap valves, a passage communicating with the delivery valves, a power pump of known type communicating with said passage. and adapted to overcome the resistance by performing a certain work, a screw-threaded rod disposed in the end of the cylinder of saidgenerating pump, said rod serving to limit the stroke of the second piston of the generating pump, a servoiotor controlled by the speed of the motor and acting upon the screw-threaded rod in order to vary the output of the generating pump: according vto the speed of the motor, whereby the motor shall be enabled to maintain its normal speed irresp'ectively of the resistance to. be overcome by the power Pumryystein of transmission of a driving effect, comprising in combination a motor, a generating pump adapted'to be driven by sai'dmotor, a piston 4'movable in the pump cylinder, a liquid filling the cylinder, a second piston disposed inH the second cylinder and movable by the pressure of the liquid,

suction and deliveryflapl valves, a passagel communicating with the delivery valves, a power pump of known type communicating with said passage -and adapted to overcome the resistance by periforming a certain work, a screw-threaded 'roddisposed in the end of the cylinder of said generating pump, said rod serving to limit the stroke of the second piston of the generating pump, a tachymetrical rcentrifugal pump keyed on the motor shaft, a cylinder containing a piston, a passage effecting communication between the liquid discharged bythe centrifugal pump and the surface of the piston, aspring with adjustable tension adapted to act upon the other surface of the piston, conduits formed in the body oic the piston, a second cylinder comn'iunicating` with said conduits of the piston, a piston movable in a second cylinder, a rod yintegral with the piston and adapted Ito act uponthe rod screwed into the end of the cylinder of the Lgenerating pump. In testimony whereof l have signed this speciiication.

ROBERT EsNAULT-Pnmnmn. 

